1. Field of the Invention
The present invention relates to an apparatus for manufacturing and a method for manufacturing a semiconductor device, and more particularly to a semiconductor device manufacturing apparatus and method for the purpose of forming, using a thermal CVD (chemical vapor deposition) method to form on a substrate a metallic film such as a film of copper or aluminum, a high dielectric coefficient layer such as a layer of titanium oxide strontium, and a ferroelectric film such as BST or TZT.
2. Description of the Related Art
In general, in fabricating a wire (a so-called damascene copper wire) by burying copper in a trench of a wiring pattern, a thermal CVD apparatus is used to deposit copper onto the substrate. FIG. 6 shows a general view of a thermal CVD apparatus in the past.
As shown in FIG. 6, a thermal CVD apparatus in the past has a hollow vacuum chamber 60, a vacuum pump 61 such as a turbomolecular pump for the purpose of exhausting the inside of the vacuum chamber 60 to a vacuum condition, a substrate holder 62, provided within the vacuum chamber 60, which holds a substrate W, a vaporizer 63 which atomizes the copper to be deposited on the substrate W as the raw gas, and a feed port 64 for the purpose of supplying the raw gas from the vaporizer 63 to within the vacuum chamber 60.
The substrate holder 62 has a substrate heating mechanism which is capable of controlling the temperature of the substrate W to within the rage from 100xc2x0 C. to 400xc2x0 C. When depositing copper, the temperature is controlled to approximately 200xc2x0 C.
Next, the method of depositing a copper film for the purpose of forming a copper wire using a thermal CVD apparatus of the past will be described. First, a trench is formed in the region in which a wire is to be formed on the silicon oxide film of the semiconductor substrate W.
Next, the above-noted substrate W is supported on top of the substrate holder 62 of the thermal CVD apparatus. The inside of the vacuum chamber 60 is brought to a vacuum condition beforehand by the vacuum pump 61.
Next, the substrate heating mechanism of the substrate holder 52 is caused to operate, so as to heat the substrate to a prescribed temperature. Simultaneously with this action, the Cu(hfac) (tmvs) raw gas, which has been vaporized by the vaporizer 63 is supplied to the supply port 64, together with a hydrogen carrier gas, and a copper film of a prescribed thickness is deposited onto the substrate W.
Then, using a CMP (chemical mechanical polishing) method, the deposited copper film is polished, so that copper remains only within the trench, thereby forming the copper wire.
In the Japanese Examined Patent Publication (KOKOKU) No. 1-19467 and the Japanese Unexamined Patent Publication (KOKAI) No. 2-119125 and in the Japanese Unexamined Patent Publications (KOKAI) Nos. 3-97871 and 3-257099, there is technology disclosed directed to the application of a voltage to a substrate holder that holds a substrate in a plasma CVD apparatus.
The major reaction of the above-described copper deposition reaction is chiefly the disproportionate reaction
2Cu+1(hfac)(tmvs)xe2x86x92Cu0+Cu+Z(hfac)2+2(tmvs).
The rate of this reaction is established by the absorption of the 2 Cuxe2x88x921 (hfac) molecules at the deposition surface and the movement of charge and removal of reaction products.
The driving forces of these rate-determining reactions are such things as the thermal energy according to the temperature of the substrate surface, and the amount of raw gas that is supplied, and it is difficult to improve the rate of reaction by means of these quantities.
The above-noted disproportionate reaction is, in principle, a reversible reaction, and it is thought that there is a limit to the control of the direction of the reaction by means of isotropic heat.
In formation of a copper wire using a thermal CVD apparatus of the past, in order to improve coverage it was necessary to lower the substrate temperature, which causes the rate of copper deposition to become slow (for example, 20 nm/minute). As a result, the time for fabrication of the semiconductor device becomes long, this resulting in a drop in productivity.
In the method of the past, because it was not possible to control the crystal orientation in the film that was formed it was difficult to deposit a film having good quality with polarity alignment.
Additionally, in order to improve the reliability of the copper wires, it is necessary to control the grain growth in the copper film. With the method of the past, however, it was difficult to control grain growth.
In the plasma CVD apparatus technology that was disclosed in the above-noted Japanese Patent Publications, a bias voltage is applied to the substrate, and ions such as argon are allowed to collide with the surface of the substrate, the purpose being to impure the film surface purity and step coverage, and improve the flatness of the film surface, this being intrinsically different from the technology of the present invention, which uses an electrostatic action or the action of an electrical current.
Accordingly, it is an object of the present invention to solve the problems noted above, and to provide an apparatus and method for manufacturing a semiconductor device, whereby it is possible to promote the deposition of a film and to control the rate of film deposition, the crystal orientation, and the growth of grains.
In order to achieve the above-noted object, the present invention has the following described technical constitution.
Note that, one aspect of the present invention is that an apparatus for manufacturing a semiconductor device which has a basic technical conception in that a semiconductor device manufacturing apparatus that uses a thermal CVD reaction to deposit a film onto a substrate, the apparatus having a power supply means that supplies electric current to the substrate or the film deposited thereupon.
And a second aspect of the present invention is that a semiconductor device manufacturing method for depositing a film on a substrate by a thermal CVD reaction, wherein the film is deposited on a substrate while a current is applied to the substrate or film deposited thereupon.
Specifically, an apparatus for manufacturing a semiconductor device according to the present invention is a semiconductor device manufacturing apparatus which uses a thermal CVD reaction to deposit a film onto a substrate, and which has a power supply that either applies a current or a potential to a substrate or to a film that is deposited onto the substrate.
An apparatus for manufacturing a semiconductor device according to the present invention is a semiconductor device manufacturing apparatus which uses a thermal CVD reaction to deposit a film onto a substrate, this apparatus having a supporting means on which the electrode terminal units are supported, comprising, for example, a rectangular or a ring like frame as well as a plate having for example, a rectangular or a ring like aperture therein, and which has an electrode terminal that makes contact with the substrate or with film that is deposited onto the substrate, a power supply that applies either a current or a potential to the electrode terminal of the ring, and means for moving the ring so that it makes contact with or is removed from the substrate or with film that is deposited onto the substrate.
The above-noted electrode unit supporting means such as the ring, can have a positive electrode terminal units to which a positive voltage is applied and a negative electrode terminal to which a negative voltage is applied, these being disposed in opposition to each other.
A plurality of the above-noted electrode terminal units can be disposed in opposition on a circle that is concentric to the supporting means, for example, the ring, the power supply applying a voltage to each electrode terminal unit, independently, a positive voltage being applied to one and a negative voltage being applied to the other of the opposing electrode terminal units, and it also being possible to sequentially switch the positive and negative voltages that are applied to adjacent electrode terminal units.
A semiconductor device manufacturing apparatus according to the present invention can also have means for monitoring the potential of the substrate or a film that is deposited thereupon, and for controlling the current or voltage or the temperature of the substrate, based on that potential.
A semiconductor device manufacturing apparatus according to the present invention preferably enables the setting of the potential of the substrate or a film that is deposited thereupon to, for example, an arbitrary ground potential or the like.
Another semiconductor device manufacturing apparatus according to the present invention is a semiconductor device manufacturing apparatus that uses a thermal CVD reaction to deposit a film onto a substrate, this apparatus having means for generating a current or a potential in the substrate or a film that is deposited thereupon, without coming into contact with the substrate or a film that is deposited thereupon.
The above-noted generating means is, for example, a magnetic generating means that applies magnetic flux to the substrate or to a film that is deposited thereupon.
A method of manufacturing a semiconductor device according to the present invention is a semiconductor device manufacturing method whereby a thermal CVD reaction is used to deposit a film onto a substrate, whereby the film is deposited as a current or a potential is applied to the substrate or to a film that is deposited thereupon.
A method of manufacturing a semiconductor device according to the present invention is additionally one in which a thermal CVD reaction is used to deposit a film onto a substrate, whereby the film is deposited as the potential of the substrate or a film deposited thereupon is set to an arbitrary ground potential.
Yet another method of manufacturing a semiconductor device according to the present invention is one in which a thermal CVD reaction is used to deposit a film onto a substrate, whereby, for example, magnetic flux are applied so as to apply a current or a potential to the substrate or a film deposited thereupon, without making contact with the substrate or the film deposited thereupon.
Yet another method of manufacturing a semiconductor device according to the present invention has:
(1) a step of depositing a film onto a substrate using a thermal CVD reaction and
(2) a step of depositing a film by using a thermal CVD reaction as a current or potential is applied to the deposited film.
Yet another method of manufacturing a semiconductor device according to the present invention has:
(1) a step of forming a trench on a semiconductor substrate,
(2) a step of depositing a barrier layer for the purpose of preventing film diffusion within the trench,
(3) a step of depositing a film onto the barrier layer by using a thermal CVD reaction,
(4) a step of depositing a film by using a thermal CVD reaction while applying a current o a potential to the deposited film, and
(5) a step of polishing the film and the barrier layer, so as to leave the film and barrier layer within the trench so as to form a wire.
According to the present invention, by applying a current or a potential to a substrate or a film that is deposited thereupon, in addition to a disproportionate reaction, a reduction reaction occurs, the deposition of the film is promoted, and it is possible to control the film deposition rate, the crystal orientation, and the grain growth.
Additionally, because the present invention can be used to set the potential of the substrate or a film that is deposited thereupon to, for example, ground potential, it is possible to obtain a uniform potential distribution generated on the surface thereof because of electrostatic chucking, for example.